Many cattle in their first or second grazing season face an increased worm threat from a potential population explosion following rain after April and May’s dry weather, according to Pfizer vet Andrew Montgomery.

He also suggested a large number of cattle may not have been dosed for worms, because of the dry start to the grazing season, and so remain at risk. Animals treated with a pour on at turnout may now need a mid-season treatment. The only exception, he adds, are those dosed already with a persistent treatment and still within the product’s duration of action. However, it will be important to ensure further treatment after the wormer persistency has finished.

“Worm infections can reduce summer growth rates well before visible signs are present,” he explained. “Maximising growth rates at grass can allow feed cost economies next winter, so a strategy that covers from now until housing can make a real impact on rearing costs.”

Mr Montgomery suggested the use of a moxidectin formulation, which farmers can use in mid-season and animals will not require additional treatments if housed within the four month persistency window.

“Speak to your animal health provider to ensure cattle are protected this season, because the risks could be higher than you think,” urges Mr Montgomery.